A typical example of these drivers is disclosed in Japanese Patent Publication No. 3474775. The driver of an IGBT (Insulated-Gate Bipolar Transistor) as an example of switching elements includes a resistive element connecting between the sense terminal and the output terminal of the IGBT, and a comparator for comparing a sense voltage defined as the voltage difference across both ends of the resistive element with a threshold voltage.
While the IGBT is in an on state, if the sense voltage exceeds the threshold voltage as a collector current output from the IGBT excessively increases as an overcurrent, the driver determines that an overcurrent flows through the IGBT, changing the IGBT from the on state to an off state. This protects the IGBT from an overcurrent, thus maintaining the reliability of the IGBT at a high level.